A crude way of calling someone a 'wanker', used heavily between employees at actual UK law firms due to the derogatory nature of being known as a scumbag lawyer like the infamous Andrew Crossley.

davenport69_4u: LOL I just sent a legal letter to some dumb kid and her parents went ballistic!!! lmao down wit all pirates
RealLawyer: You sound like you're practicing for ACS Law, you utter simpleton.

ACS Law is (soon to be 'was') a law firm specialising in indiscriminately sending threatening emails to people they believe to be illegal file sharers. Although their most noted case prior to 2009 was the defence of a British national accused of public indecency in Dubai, they are better known for noobing up their security and having their internal emails leaked.